“Partial solid nodular shadows in the posterior basal segment of the lower lobe of the left lung” is mostly a description of lung imaging, and this type of nodule is a medium-high risk nodule, which is more serious among lung nodules. These nodules are classified into three categories according to the density of lung nodules: partially solid nodules, ground-glass nodules, and solid nodules. Among them, partially solid nodules have the highest risk of cancer. According to the Chinese Guidelines for Classification, Diagnosis and Treatment of Lung Nodules, the risk assessment and recommendations for partially solid lung nodules of different sizes are as follows: Partial solid nodules with a diameter of >8 mm are defined as high-risk nodules, and should be diagnosed by multidisciplinary consultation to decide whether further examination is needed to clarify the diagnosis, surgical resection, or CT review after 3 months. Partial solid nodules ≤8 mm in diameter were defined as intermediate-risk nodules, and continuous thin-layer CT scanning with thin-layer 3D reconstruction of the nodule was recommended at 3, 6, 12, and 24 months. Surgery was recommended if the nodule was of a growing nature, and no change or shrinkage was recommended with continued long-term CT follow-up of not less than 3 years. If partial solid nodules are found in the posterior basal segment of the lower lobe of the left lung, it is important to pay attention to them and go to a regular hospital for further diagnosis and treatment in a timely manner.